1. Field of Invention
The present invention relates to a backlight module. More particularly, the present invention relates to a side type backlight module.
2. Description of Related Art
In response to the increasing demand of displays, the manufacturers in the industry put great efforts in the development of displays. Among the displays, the cathode ray tube (CRT) has dominated the display market for many years due to its high display quality and mature technology. However, the rising “environmental protection” awareness is against its power consumption and radiation disadvantage, and the limited flattening capability is against the market demands of light, thin, short, small, chic, and power-saving displays. Therefore, the thin film transistor liquid crystal display (TFT-LCD), having superior properties such as high image quality, good space utilization, low power consumption, and no radiation, has become the mainstream display product of the market.
A TFT-LCD module mainly comprises a liquid crystal display panel (LCD panel) and a backlight module. The LCD panel usually comprises a thin film transistor array substrate, a color filter substrate, and a liquid crystal layer disposed between the two substrates. The backlight module is used to provide the surface light source required by the LCD panel to make the LCD module achieve a display effect. Moreover, backlight modules can be classified into side type backlight modules and direct type backlight modules. The side type backlight modules are taken as an example for illustration as follows.
FIG. 1A is a top view of the conventional side type backlight module, and FIG. 1B is a cross-sectional view of the conventional side type backlight module of FIG. 1A. Referring to FIG. 1A and FIG. 1B, the conventional side type backlight module comprises a back plate 130, a flexible printed circuit (FPC) 150, a plurality of white light emitting diodes (LED) 120, a light guide plate (LGP) 110, a reflecting plate 160, a plurality of optical films 10, and a sealant 140. The LGP 110 is disposed in the back plate 130, and the reflecting plate 160 is disposed between the LGP 110 and the back plate 130. The white light LED 120 is disposed on the FPC 150 and beside the LGP 110. Moreover, the sealant 140 is disposed on the back plate 130, and the optical film 170 is disposed between the sealant 140 and the LGP 110.
More particularly, the white light LED 120 is a point light source, and the light emitted by the white light LED 120 becomes a surface source after passing through the LGP 110. The LCD display adopting the conventional side type backlight module may cause problems such as insufficient color saturation.
In view of the above problems, an architecture of a set of red LED, blue LED, and green LED is provided to substitute the white light LED 120 of the side type backlight module.
FIG. 1C is an exploded view of the conventional side type LCD backlight module. Referring to FIG. 1C, the architecture of the side type backlight module is substantially the same as that of the backlight module of FIG. 1A and FIG. 1B, and the main difference lies in that the side type backlight module of FIG. 1C adopts a green LED 120g, a red LED 120r, and a blue LED 120b, so as to blend lights to be a white light.
However, since the lights emitted by the green LED 120g, the red LED 120r, and the blue LED 120b cannot be fully uniformly blended in the LGP, a partial color shift may occur in the LCD display adopting the side type backlight module.